Merge "Remote Submix Out is not a permanently attached device, and thus requires a non-empty string for its connection." am: c3c62a1eb8

Original change: https://android-review.googlesource.com/c/platform/frameworks/av/+/2393575

Change-Id: Ieaa5fb965748f55e64185a03d8a45f56e3939b5c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>